CVE intelligence and bounded remediation

CVE-2025-34157 — Coolify versions prior to v4.0.0-beta.420.6 are vulnerable to a stored cross-site scripting (XSS) attack in the project creation workflow

Critical CVSS 9.4

Coolify versions prior to v4.0.0-beta.420.6 are vulnerable to a stored cross-site scripting (XSS) attack in the project creation workflow. An authenticated user with low privileges can create a project with a maliciously crafted name containing embedded JavaScript. When an administrator attempts to delete the project or its associated resource, the payload executes in the admin’s browser context. This results in full compromise of the Coolify instance, including theft of API tokens, session cookies, and access to WebSocket-based terminal sessions on managed servers.

Severity
Critical
CVSS
9.4 (4.0)
Published
2025-08-27
CISA KEV
Not currently listed
Ecosystem
javascript/npm
Weaknesses
CWE-20, CWE-79

Affected products

  • coollabs / coolify
  • coollabs / coolify / 4.0.0

Showing 2 representative product identities from 408 source matches. Confirm exact affected versions with the linked vendor and NVD evidence.

Matched remediation archetype

Cross-site scripting and unsafe browser output

This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.

Check exposure

  • Trace reflected, stored, and DOM-derived untrusted values into HTML, attributes, URLs, styles, scripts, and client-side template sinks.
  • Identify affected origins, authenticated user roles, sensitive browser capabilities, and where content is shared across tenants.
  • Review framework escaping, rich-text sanitization, legacy templates, and client-side rendering paths.

Remediate safely

  • Use context-aware framework output encoding and safe DOM APIs; keep untrusted data out of executable contexts.
  • Sanitize intentionally supported markup with a maintained allowlist policy and validate URLs and attributes separately.
  • Update affected rendering components and add tests for every output context using inert sentinel markup.

Authoritative sources

Complete CVE record and remediation plan

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